1. Field of the Invention
The present invention relates an image input apparatus comprising an electric pan head, which pivotally supports a camera unit.
2. Related Background Art
FIG. 12 shows an example of an image input apparatus of this type. An image input apparatus 100 comprises a camera unit 101 and an electric pan head 102 for pivotally supporting the camera unit 101. According to this image input apparatus 100, the attitude of the camera unit can be controlled even from a distant place via remote control by, e.g., a remote controller, and such apparatus can be applied to a monitoring system, unmanned photographing system, and the like.
Most conventional electric pan heads allow rotations in two directions, i.e., in directions parallel to and perpendicular to their setting surfaces (the former operation will be referred to as panning hereinafter, and the latter operation will be referred to as tilting hereinafter). With this feature, in the case of the image input apparatus with the camera unit, nearly all the directions around the setting position of the image input apparatus can be photographed.
However, for example, when the setting place of the image input apparatus is not flat or is a plane inclined at a given angle from the horizontal plane, the setting surface of the electric pan head at that time is not parallel to the horizontal plane. For this reason, photographing is made while the setting surface is inclined. Also, for example, when an object that is moving on the horizontal plane is traced and photographed while moving the electric pan head, if the panning path of the camera unit is not parallel to the horizontal plane, the photographing operation may fail.